Impact of Cover Crops on Soil Moisture in Semi-Arid Cotton Systems.

Interest in cover crops has recently grown throughout the nation. As interest has increased within semi-arid regions of Texas, producer’s top concern has focused on the impact that cover crops has on soil moisture.  The objective of this research is to quantify the impact of cool-season cover crops in cotton cropping systems on soil moisture and subsequent lint yields.  Both dryland and irrigated cotton systems were evaluated.  The dryland system consists of seven treatments: 1) conventional tillage without a cover crop; 2) no-till without a cover crop; and no-till with cover crops consisting of 3) crimson clover; 4) Austrian winter field pea; 5) hairy vetch; 6) wheat, and 7) legume/grass cover crop mixture. The irrigated system consists of four treatments: 1) conventional tillage without a cover crop; 2) no-till without a cover crop; 3) no-till with a wheat cover crop; and 4) no-till with a legume/grass cover crop mixture. Neutron probes were inserted into each plot and soil moisture is evaluated bi-weekly throughout the year.  The cover crop mixture produced the highest biomass in each system.  Furthermore, available soil moisture was significantly lower for the cover crop mixture compared with all other treatments except the wheat cover in the irrigated system.  However, subsequent cotton lint yields were not significantly different between the mixed cover crop treatment and other cover crop treatments.